1. Field of the Invention
This invention relates to a moving "S" fiber array optical switch and, in particular, to a fully-reversing 2.times.2 electromechanical optical switch apparatus in which input optical signals carried on input optical fibers can be selectively transmitted to output optical fibers. Accordingly, it is a general object of this invention to provide new and improved switch apparatus of such character.
2. General Background
Mechanical optical switching devices have been described in the literature. For example, U.S. Pat. No. 4,239,331 to Aoyama, issued Dec. 16, 1960, discusses an optical switching device for use with optical fibers. The fibers are positioned on input and output sides of the switch, with each fiber terminated by a lens for collimating incident light emitted from an input optical fiber. At least one transparent dielectric plate, with a uniform refractive index, is disposed between lenses associated with the input and the output sides of the switch. The transparent plate changes the optical transmission path of the collimated light beam when present in a light transmission path. When the transparent dielectric plate is driven into the light transmission path, the optical axis is switched from one to a different output optical fiber.
Mechanical optical switching devices are disclosed in U.S. Pat. No. 4,322,126 to Minowa et al. There, a mechanical optical switching device has a plurality of input optical fibers coupled to the input side thereof for receiving incoming light beam signals. Individually associated with each optical fiber is an input collimating lens which is positioned to receive the incoming light beam and to convert it into parallel light beams. Optical path-switching means, having uniform refractive index, are disposed at the rear or output of the input lens for switching the optical paths of the collimated light beams emerging from the input lens beam. A plurality of output optical fibers have individually associated output lenses for focusing the parallel light beams, after they have passed through the position controlled by the optical path-switching means. An electrically controlled, mechanical switching device selectively inserts or removes the optical path-switching means into or away from a predetermined position in order to switch light from any incoming fiber to any outgoing fiber.
U.S. patent application Ser. No. 129,502, filed Dec. 7, 1987, entitled "Fiber Optical Switch", (U.S. Pat. No. 4,790,621) assigned to GTE Products Corporation, discloses a 2.times.2 optical switch which employs a six-faced prism that can be moved from a first position to a second position. Mechanical latching means were used to maintain the second position without the necessity of applying continuous power to the moving means which preferably is a solenoid.